regexparser.java

java1.6众多例子参考

    }
    Token processBacksolidus_z() throws ParseException {
        this.next();
        return Token.token_stringend;
    }
    Token processBacksolidus_b() throws ParseException {
        this.next();
        return Token.token_wordedge;
    }
    Token processBacksolidus_B() throws ParseException {
        this.next();
        return Token.token_not_wordedge;
    }
    Token processBacksolidus_lt() throws ParseException {
        this.next();
        return Token.token_wordbeginning;
    }
    Token processBacksolidus_gt() throws ParseException {
        this.next();
        return Token.token_wordend;
    }
    Token processStar(Token tok) throws ParseException {
        this.next();
        if (this.read() == T_QUESTION) {
            this.next();
            return Token.createNGClosure(tok);
        } else
            return Token.createClosure(tok);
    }
    Token processPlus(Token tok) throws ParseException {
        // X+ -> XX*
        this.next();
        if (this.read() == T_QUESTION) {
            this.next();
            return Token.createConcat(tok, Token.createNGClosure(tok));
        } else
            return Token.createConcat(tok, Token.createClosure(tok));
    }
    Token processQuestion(Token tok) throws ParseException {
        // X? -> X|
        this.next();
        Token par = Token.createUnion();
        if (this.read() == T_QUESTION) {
            this.next();
            par.addChild(Token.createEmpty());
            par.addChild(tok);
        } else {
            par.addChild(tok);
            par.addChild(Token.createEmpty());
        }
        return par;
    }
    boolean checkQuestion(int off) {
        return off < this.regexlen && this.regex.charAt(off) == '?';
    }
    Token processParen() throws ParseException {
        this.next();
        int p = this.parennumber++;
        Token tok = Token.createParen(this.parseRegex(), p);
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // Skips ')'
        return tok;
    }
    Token processParen2() throws ParseException {
        this.next();
        Token tok = Token.createParen(this.parseRegex(), 0);
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // Skips ')'
        return tok;
    }
    Token processCondition() throws ParseException {
                                                // this.offset points the next of '('
        if (this.offset+1 >= this.regexlen)  throw ex("parser.factor.4", this.offset);
                                                // Parses a condition.
        int refno = -1;
        Token condition = null;
        int ch = this.regex.charAt(this.offset);
        if ('1' <= ch && ch <= '9') {
            refno = ch-'0';
            this.hasBackReferences = true;
            if (this.references == null)  this.references = new Vector();
            this.references.addElement(new ReferencePosition(refno, this.offset));
            this.offset ++;
            if (this.regex.charAt(this.offset) != ')')  throw ex("parser.factor.1", this.offset);
            this.offset ++;
        } else {
            if (ch == '?')  this.offset --; // Points '('.
            this.next();
            condition = this.parseFactor();
            switch (condition.type) {
              case Token.LOOKAHEAD:
              case Token.NEGATIVELOOKAHEAD:
              case Token.LOOKBEHIND:
              case Token.NEGATIVELOOKBEHIND:
                break;
              case Token.ANCHOR:
                if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
                break;
              default:
                throw ex("parser.factor.5", this.offset);
            }
        }
                                                // Parses yes/no-patterns.
        this.next();
        Token yesPattern = this.parseRegex();
        Token noPattern = null;
        if (yesPattern.type == Token.UNION) {
            if (yesPattern.size() != 2)  throw ex("parser.factor.6", this.offset);
            noPattern = yesPattern.getChild(1);
            yesPattern = yesPattern.getChild(0);
        }
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();
        return Token.createCondition(refno, condition, yesPattern, noPattern);
    }
    Token processModifiers() throws ParseException {
                                                // this.offset points the next of '?'.
                                                // modifiers ::= [imsw]* ('-' [imsw]*)? ':'
        int add = 0, mask = 0, ch = -1;
        while (this.offset < this.regexlen) {
            ch = this.regex.charAt(this.offset);
            int v = REUtil.getOptionValue(ch);
            if (v == 0)  break;                 // '-' or ':'?
            add |= v;
            this.offset ++;
        }
        if (this.offset >= this.regexlen)  throw ex("parser.factor.2", this.offset-1);
        if (ch == '-') {
            this.offset ++;
            while (this.offset < this.regexlen) {
                ch = this.regex.charAt(this.offset);
                int v = REUtil.getOptionValue(ch);
                if (v == 0)  break;             // ':'?
                mask |= v;
                this.offset ++;
            }
            if (this.offset >= this.regexlen)  throw ex("parser.factor.2", this.offset-1);
        }
        Token tok;
        if (ch == ':') {
            this.offset ++;
            this.next();
            tok = Token.createModifierGroup(this.parseRegex(), add, mask);
            if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
            this.next();
        } else if (ch == ')') {                 // such as (?-i)
            this.offset ++;
            this.next();
            tok = Token.createModifierGroup(this.parseRegex(), add, mask);
        } else
            throw ex("parser.factor.3", this.offset);

        return tok;
    }
    Token processIndependent() throws ParseException {
        this.next();
        Token tok = Token.createLook(Token.INDEPENDENT, this.parseRegex());
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // Skips ')'
        return tok;
    }
    Token processBacksolidus_c() throws ParseException {
        int ch2;                                // Must be in 0x0040-0x005f
        if (this.offset >= this.regexlen
            || ((ch2 = this.regex.charAt(this.offset++)) & 0xffe0) != 0x0040)
            throw ex("parser.atom.1", this.offset-1);
        this.next();
        return Token.createChar(ch2-0x40);
    }
    Token processBacksolidus_C() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_i() throws ParseException {
        Token tok = Token.createChar('i');
        this.next();
        return tok;
    }
    Token processBacksolidus_I() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_g() throws ParseException {
        this.next();
        return Token.getGraphemePattern();
    }
    Token processBacksolidus_X() throws ParseException {
        this.next();
        return Token.getCombiningCharacterSequence();
    }
    Token processBackreference() throws ParseException {
        int refnum = this.chardata-'0';
        Token tok = Token.createBackReference(refnum);
        this.hasBackReferences = true;
        if (this.references == null)  this.references = new Vector();
        this.references.addElement(new ReferencePosition(refnum, this.offset-2));
        this.next();
        return tok;
    }

    // ----------------------------------------------------------------

    /**
     * factor ::= ('^' | '$' | '\A' | '\Z' | '\z' | '\b' | '\B' | '\<' | '\>'
     *            | atom (('*' | '+' | '?' | minmax ) '?'? )?)
     *            | '(?=' regex ')'  | '(?!' regex ')'  | '(?&lt;=' regex ')'  | '(?&lt;!' regex ')'
     *            | '(?#' [^)]* ')'
     * minmax ::= '{' min (',' max?)? '}'
     * min ::= [0-9]+
     * max ::= [0-9]+
     */
    Token parseFactor() throws ParseException {        
        int ch = this.read();
        Token tok;
        switch (ch) {
          case T_CARET:         return this.processCaret();
          case T_DOLLAR:        return this.processDollar();
          case T_LOOKAHEAD:     return this.processLookahead();
          case T_NEGATIVELOOKAHEAD: return this.processNegativelookahead();
          case T_LOOKBEHIND:    return this.processLookbehind();
          case T_NEGATIVELOOKBEHIND: return this.processNegativelookbehind();

          case T_COMMENT:
            this.next();
            return Token.createEmpty();

          case T_BACKSOLIDUS:
            switch (this.chardata) {
              case 'A': return this.processBacksolidus_A();
              case 'Z': return this.processBacksolidus_Z();
              case 'z': return this.processBacksolidus_z();
              case 'b': return this.processBacksolidus_b();
              case 'B': return this.processBacksolidus_B();
              case '<': return this.processBacksolidus_lt();
              case '>': return this.processBacksolidus_gt();
            }
                                                // through down
        }
        tok = this.parseAtom();
        ch = this.read();
        switch (ch) {
          case T_STAR:  return this.processStar(tok);
          case T_PLUS:  return this.processPlus(tok);
          case T_QUESTION: return this.processQuestion(tok);
          case T_CHAR:
            if (this.chardata == '{' && this.offset < this.regexlen) {

                int off = this.offset;          // this.offset -> next of '{'
                int min = 0, max = -1;

                if ((ch = this.regex.charAt(off++)) >= '0' && ch <= '9') {

                    min = ch -'0';
                    while (off < this.regexlen
                           && (ch = this.regex.charAt(off++)) >= '0' && ch <= '9') {
                        min = min*10 +ch-'0';
                        if (min < 0)
                            throw ex("parser.quantifier.5", this.offset);
                    }
                }
                else {
                    throw ex("parser.quantifier.1", this.offset);
                }

                max = min;
                if (ch == ',') {

                   if (off >= this.regexlen) {
                       throw ex("parser.quantifier.3", this.offset);
                   }
                   else if ((ch = this.regex.charAt(off++)) >= '0' && ch <= '9') {                       

                        max = ch -'0';       // {min,max}
                        while (off < this.regexlen
                               && (ch = this.regex.charAt(off++)) >= '0'
                               && ch <= '9') {
                            max = max*10 +ch-'0';
                            if (max < 0)
                                throw ex("parser.quantifier.5", this.offset);
                        }

                        if (min > max)
                            throw ex("parser.quantifier.4", this.offset);
                   }
                   else { // assume {min,}
                        max = -1;           
                    }
                }

               if (ch != '}')
                   throw ex("parser.quantifier.2", this.offset);

               if (this.checkQuestion(off)) {  // off -> next of '}'
                    tok = Token.createNGClosure(tok);
                    this.offset = off+1;
                } else {
                    tok = Token.createClosure(tok);
                    this.offset = off;
                }

                tok.setMin(min);
                tok.setMax(max);
                //System.err.println("CLOSURE: "+min+", "+max);
                this.next();
            }
        }
        return tok;
    }

    /**
     * atom ::= char | '.' | char-class | '(' regex ')' | '(?:' regex ')' | '\' [0-9]
     *          | '\w' | '\W' | '\d' | '\D' | '\s' | '\S' | category-block
     *          | '(?>' regex ')'
     * char ::= '\\' | '\' [efnrt] | bmp-code | character-1
     */
    Token parseAtom() throws ParseException {
        int ch = this.read();
        Token tok = null;
        switch (ch) {
          case T_LPAREN:        return this.processParen();
          case T_LPAREN2:       return this.processParen2(); // '(?:'
          case T_CONDITION:     return this.processCondition(); // '(?('
          case T_MODIFIERS:     return this.processModifiers(); // (?modifiers ... )
          case T_INDEPENDENT:   return this.processIndependent();
          case T_DOT:
            this.next();                    // Skips '.'
            tok = Token.token_dot;
            break;

            /**
             * char-class ::= '[' ( '^'? range ','?)+ ']'
             * range ::= '\d' | '\w' | '\s' | category-block | range-char
             *           | range-char '-' range-char
             * range-char ::= '\[' | '\]' | '\\' | '\' [,-efnrtv] | bmp-code | character-2
             * bmp-char ::= '\' 'u' [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F]
             */
          case T_LBRACKET:      return this.parseCharacterClass(true);
          case T_SET_OPERATIONS: return this.parseSetOperations();

          case T_BACKSOLIDUS:
            switch (this.chardata) {
              case 'd':  case 'D':
              case 'w':  case 'W':
              case 's':  case 'S':
                tok = this.getTokenForShorthand(this.chardata);
                this.next();
                return tok;

              case 'e':  case 'f':  case 'n':  case 'r':
              case 't':  case 'u':  case 'v':  case 'x':
                {
                    int ch2 = this.decodeEscaped();
                    if (ch2 < 0x10000) {
                        tok = Token.createChar(ch2);
                    } else {
                        tok = Token.createString(REUtil.decomposeToSurrogates(ch2));
                    }
                }
                break;

              case 'c': return this.processBacksolidus_c();
              case 'C': return this.processBacksolidus_C();
              case 'i': return this.processBacksolidus_i();
              case 'I': return this.processBacksolidus_I();